This application is a request for partial funds to establish a neuropeptide laboratory at the Institute for Advanced Biomedical Research at the Oregon Health Sciences University and to provide grant support for basic neurobiological studies on opioid peptides and their processing enzymes. These funds are requested to enable the Principal Investigator to continue and extend the work he has begun while he was a member of the Nancy Pritzker Laboratory of Behavioral Neurochemistry at Stanford Medical Center. The research that is proposed consists of four sections: 1. Further biochemical and immunohistochemical characterization of the prodynorphin neuronal system. 2. Further biochemical and immunohistochemical characterization of the proenkephalin neuronal system. 3. Isolation and characterization of 2 putative proteolytic processing enzymes involved in peptide hormone precursor maturation. 4. Synthesis and characterization of novel photoreactive opioid peptides that can be used--in conjunction with specific antibodies--as immunological probes for opioid receptors. The methods that we are applying in these research projects include: peptide synthesis, antibody production, radioimmunoassay, chromatography techniques including HPLC and affinity chromatography, amino acid composition analysis and gas phase amino acid sequencing, peptide and protein isolation, radioreceptor assays, immunohistochemistry, as well as general techniques in protein and peptide chemistry and biochemistry. Endogenous opioids constitute one of the major neuropeptide systems in the mammalian organism. The questions we are attempting to answer will, therefore, be relevant to general problems of mental and neurological disorders by investigating basic principles of the biochemistry and anatomy of opioid peptides, their receptors and their processing enzymes.